Half duplex telegraph repeater, including break feature



Sept 2 1952 Y vw. T.v REA 2,609,453 L HALF DUPLEX TELEGRAPH REFEATER,INCLUDING BREAK FEATURE Filed sept. 27. 1949` a sz TOOTHER smo/Nc Hua/NVENTOR ATTORNEY Patented Sept. 2, 1952 UNVrliz'lov STATES PATENTOFFICE HALF DUPLEX TELEGRAPH REPEATR, INCLUDING` BREAK FEATURE Wilton'fr; Rea, Manhasset, N. Y., assigner tenen Telephone;v Laboratories,Incorporated; New York; N. Y., ay corporation of New York.`Application-September 27, 1949, serial Nb; iis-,118' reinas: (c1.'178;70)

magnetic relay type, which vrepeittei circuit has" but two relays,namelyga sendngrelafard a r'- ceiving relay, and Whihl repeater'includes a break feature While ha'lirlg no break relai;` or equivalentindividual switching elirient' to per'- form the break function. Therepeaterof'the present invention is arranged sthat it in'af'be connectedthrough a" carrier, metallic or ground'- ed telegraph channel, or" aiix'illdei` r' conhities are' Well known itliV it, t a-ciesp'dingrepeater', toV interconnect ti/Vb Subscribers telegraph loop circuitstgether, one'atach end of the system. The prsentre'peater'afkehi ployedalso to interconriec t^ a telegraph sub'- scribers station circuitandfits`4 a'ssiated loop through a hub-type telegraph Ytitrl circuitinto' a telegraph hub concentration,comprising"other' telegraph loopsand lines; Huh-typetelegrapl repeaters are Well known the art, beingshow-n for instance in Patents zjpeaztmgissd to'jr'f.' s Knke'ad etal.,October` 3, 1936721069224, issued 496, issued to" nie' Decerb'er 21,1943. I'nintr'- connecting the present' repeater into a'vl-btyp'etelegraph concentration, y a telegraph" lil re'- peater control circuitof the electrnictype, suchV ence to the drawing which'-sliiiis"the"repatei*y circuit of the presentintenijii'ol'i''.`A l K Inthe drawing a-telegraphs'uhscib'rs station is shown at the right' whichisV interconnected through tw'o con'ductr's"forming-'tileV loop't 'the'subscribers loop repeater shown inthe middle" of the drawing, which looprepeater-'is' located at a telegraphv repatrstatin. Th'looprepeater maybe conectd'acrding tothe sriice required either through a hub-typetelegraph repeater circuit tol a hub repeater Vconcentration or throughthe more conventional tandem-'telegraph channel arrangement;V This is"indicated hyv switches Sl and Sit. In their-*lower positions switches-SIandSZ-engage terminalsl and-2; respectively, leading through a hub-typetelegraph repeater ircilt' to the r"ceii'`igd Euh s'ilill ing' hub,-vrespedtteltl p Cithe'rr telegraph sub'# scr'bers stations'I and othertelegraphhline facili-l ties will also be connected into the telegraphrepeaterV concentration. Thisiskinlicatedliykthe short' spur'connections at thetop and hottonof thef receiving`v and sen'din'gfhles'.y A l, g

If switches si arie s2 engage terminals' sana 4 theY mp5 repeater' isciiiiejted through tele-U graph' line repeaterv z'a'lnfd a telegraphchannel to a distaxit'rpsatr; Tiisf repeaters Merian-i nels" are"c6nteiltiall andv` iayhe of ay'f a variety Aoff'nsiill-kn'ovi he art. KA) The loop" repetr'issliow in the condition which it assine tif "enidle o" duringthere'ceptisii ofjaY marking igiiai element,tatat'iiutmiia-Y tui'e'cf its" reeei'v relai/'R' and sfvitsjse' f Irelay/S eachA engagement' tn its repec ivf'" rightQhad (if,ri'aliigvcon-tact hey n-diaccents tery. Since the batteries connected to the endsof the loop are of opposite polarities, full line current iiows throughthe loop and through the top Winding of the receiving relay R for thiscondition and its eiect tends to actuate its armature to engage itsright-hand or marking contact M. From the apex of relay R a biasingcircuit extends through its lower Winding and resistance Il to ground.The effect of the current in the biasing circuit tends to actuate thearmature of relay R to engage with its left-hand or spacing contact S,but the effect of the current in the upper Winding of relay R isdominant for this condition and the armature of relay R is actuated toor maintained in engagement with its right-hand or marking contact M.When line current iiovvs through receiving magnet Vi a marking signal isreceived at the station.

While receiving relay R is in engagement with its marking contact M, acircuit is established For the transmission of a spacing signal fromthe'hub-type telegraph repeater, negative battery is connected in thehub-type repeater to the circuit extending through the top Winding oi'the sending relay S. The effectof this current v tends to actuate thearmature of sending relay S to engage its left-hand or spacing contact Sand this eiect is dominant over the counter eiect in the biasing windingso that the armature of relay S is actuated to engage its spacingcontact.v

This establishes a circuit extending from positive battery through theright-hand or marking contact M and armature of relay R, conductor i6,left-hand or spacing contact S and the armature of sending relay S, fromwhich point the circuit has been traced around theloop and through thebiasing winding of relay R. For this condition both ends of the loop areterminated in the same positive battery so that no current ows aroundthe loop and through the top winding of receiving relay R. When negativebattery was connected to the apex of relay R for the marking condition,its effect in the biasing Winding tended to actuate the armature ofrelay R toward its spacing contact. Now, with positive battery connectedto the apex of relay R. the effect in the biasing winding is reversedand is such as to tend to maintain the armature of relay R in engagementwith its right-hand or marking contact M. Since this eiect is unopposed,as there is no current in the top winding of relay R, the armature relayR will be maintained on its righthand or marking contact. When nocurrent flows through receiving magnet il' a spacing signal is receivedat the subscribers station.

In transmitting from the subscribers station toward the loop repeater,for a marking signal, the condition is the same as described for amarking signal transmitted toward the subscribers station. For a spacingsignal the teletypevvriter transmitting contacts i8 are opened, openingthe loop. No current ows in the loop or through the top Winding ofreceiving relay R. Since the sending relay S is in engagement with itsrighthand or marking contact M for this condition, negative battery isconnected to the apex of receiving relay R. The effect of this in thebottom or biasing Winding of relay R,y as has been explained, tends toactuate the armature of relay R to engage its left-hand or spacingcontactand,

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4 since for this condition it is unopposed, the ar` mature of receivingrelay R Will be actuated to engage with its left-hand or spacing contactS. Negative battery is, therefore, connected through the spacing contactand armature of relay R, resistance 5, switch Sl, terminal l and intothe hubtype telegraph repeater to .propagate a spacing signal to thereceiving hub. s

It Will now be assumed that the subscriber at the telegraph subscribersstation shown at the right in the drawing is transmitting and at themoment is transmitting a marking signal element toward the loop repeaterand another of the subscribers connected through the hub Wishes to breakand transmits a long spacing signal through the hubto sending relay S.This will actuate the armature of relay S to spacing in a manner whichhas been described. Since the armature of receiving relay R will be inengagement with its marking contact M, positive battery will beconnected through the marking contact and armature of relay R,conductori6, and spacing contact S of relay S to oneend of the loop While theopposite end ofthe loop is terminated in the same positive battery. Nocurrent will therefore now in the loop or through receiving magnet l1,and a spacing signal will be received by receiving magnet yIl. Thearmature of relay R vvill be maintained 'in yengagement with its markingcontact bythe effect of positive battery flowing through its bottom orbiasing Winding. If transmitting contacts I3 are now opened in anattempt to transmit a spacing signal it will be ineffectual, since thereis no current in the top Winding of relay R to be interrupted and thearmature of relay R willcontinue to be maintained in engagement With itsmarking contact M.

If a spacing signal element is being transmitted from transmittingcontacts I8v when a long space or break signalarrives at sending relayS, it Will not be possible to'break immediately. The reason for this isthat When the armature of relay S is actuated to its spacing contact,since the armature of receiving relay R Will be in engagement with itsleft-hand or spacing contact S, in response to the spacing signal fromcontacts i8, negative battery vvillcbev connected through the spacingcontact and armatureY of relay R, conductor I6, spacing contact S andarmature of relay S and inductancle'` 9 to. theapex oi. relay R. Thepath around theloop vvill be open at contacts l 8 which are assumed tobe open for the transmission of a spacing signal. With negative batteryconnected to the apex of relay R and no current in its top Winding theeiect of the current in the biasingwinding Will .be such as to tend toactuate the armature of relay Rto its spacing contact. AThe spacingsignal being received by relay RV Willbe unaiected by the reception of abreak signal by relay S. In other Words it is not possible to breakagainst a break.

When contacts I8 are reclosed for the transmission of the succeedingmarking signal element. the break signal, or long spacing signal, beingreceived by relay S will be propagatedto the subv scribers station.

If signals are incoming from the hub through sending relay S toreceiving magnet VI'I at the subscribers station .and transmittingcontacts i8 are opened to transmit along spacel or break signal, if amarking signal is at the moment being transmitted from relay S, thearmature of relay R will be actuated to its spacing contact as for anyspacing signal transmittedfrom the subscribers station. The armature ofrelay-Rwillmaintained @on ias spacing Contact wasn line amature 'ofrelay `attempts to itfassma 'the sweeter-ng eingang sha1 nement-feintenegative,

battery willlbefsupplied through thes'acing contacts and armatures ofrela-ysR and V"S `to the biasing "winding of relay R. A long '-fspacinfgl'sig-- na'l willjbe transmitted into the 'hub telegraph repeaterv'break signal. S'uc'ced-ihigmarlig andspacip signaijsincming-tofreiay swm have no eiect on-relay-R, since as long as relay R remains spacing,negative,l battery is connected to both contacts Vof vrelay S.

If the left-hand or spacing contact of relay S were connected solidly topositive `battery,rather than havingits battery polarity controlled bythe position of the"armature`'of vrelaylggwthe break feature would belacking Vand theiollowing would occur: inthe Ypresenccof anopen'cordition at contacts I8, signals incoming from the line repeaterto relay S would be repeated back to the line repeater by relay R, butin inverted form. This is because relay R, in the absence of current inits upper winding, is subject to the current in its lower winding.Therefore, with relay S on its right-hand or marking contact, theapplication of negative battery to the lower winding of relay R wouldactuate relay R to its lefthand or spacing contact, and when relay Smoved to its left-hand or spacing contact the application oi positivebattery to said Winding would actuate relay R to its right-hand ormarking contact. Hence the distant station would receive its own signalsin inverted form, rather than the clean open or break signal which thenear station attempted to transmit.

If a spacing signal is incoming from the hub and the armature of relay Sis in engagement with its spacing contact S when transmitting contactsI8 are opened to transmit a long space or break signal toward the hub,the armature of relay R will be maintained in engagement with itsmarking contact M until the end of the spacing signal element, aspositive battery will be connected through the marking contact andarmature of relay R and the spacing contact and armature of relay S tothe apex of relay R. Current flowing through the biasing winding ofrelay R for this condition, while no current flows in its top winding,as the loop is open at contacts I8, will maintain the armature of` relayR in engagement with its marking contact M. When the armature of relay Sis next actuated to marking, the long spacing or break signal fromcontacts I8 will be propagated into the hub circuit.

For connection to the more conventional single telegraph channel througha telegraph line repeater the local side of the line repeater isarranged in a well-known manner with a receiving leg and a sending legwhich terminate on terminals 3 and t. Switches SI and S2 are actuated toengage terminals 3 and 4, respectively. The conditions imposed on theloop repeater by the telegraph line repeater and vice versa forcommunication signals and for breaking are the same as described in theforegoing for connection with the hub repeater.

The inductance 9 and the grounded condenser 8 connected to the lowerterminal of the inductance are provided to improve the wave shape of thesignals and to protect the contacts of relay S from erosion.

What is claimed is:

1. A telegraph subscribers station, a magnetic relay telegraph looprepeater, a telegraph loop georges 6 'interconnectingfsaid :Station andl:said Irep'eater, a telegraph line repeater, -a sen leg Iand`alreyceivifng leg interconnecting jsaid vloop "repeater 'and said flinerepeater, "a receiving relay-and -a ending rela 'in sad Y16 @gaat la@:vv-11nding'- on 4said arecei relayl l'c onniected fin series in-jsaidloo' tofsigfnalslfrorn said loop,

s a A n s 'on;sai`dfsefridi ng Qrel'ay 'to thef'iixed end Y'"oi'saidfarmature iin said v'receiving relay, to afford a break feature in atwo-relay repeater.

2. In a telegraph loop repeater, a sending relay, a receiving relay, anarmature on each of said relays, a rst circuit path extending directlyfrom battery of a iirst polarity through a first contact and saidarmature of said sending relay, through an operating winding of saidreceiving relay, through a subscribers telegraph loop'circuit and backto battery of a second polarity for a rst signaling condition, a secondcircuit path extending from battery of said second polarity directlythrough a iirst contact and said armature of said receiving relay,through a second contact and said armature of said sending relay for asecond signaling condition, a sending leg extending from a secondtelegraph repeater through an operating winding of said sending relay, areceiving leg extending from said armature of said receiving relay intosaid second repeater and a biasing circuit extending from said armatureof said sending relay through a biasing winding on said receiving relay.

3. In a telegraph repeater system, a subscribers telegraph station, amagnetic relay telegraph repeater, a line, a telegraph loop connectingsaid subscribers station and said repeater, a sending leg and areceiving leg interconnecting said repeater and said line, a receivingrelay and a sending relay in said repeater, said sending relay includingan operating Winding, -a biasing winding and an armature responsive tosaid windings to transmit communication signals through said telegraphloop to said station when signals are impressed by said line on saidsending leg, said receiving relay having a line winding, a biasing meansand an armature responsive thereto to transmit signals through saidreceiving leg to said line in response to signals incoming from saidtelegraph loop, a marking and a spacing contact on each of said relays,batteries of opposed polarities connected to said contacts of saidreceiving relay, battery of the same potelegraph repeater, a magneticrelay telegraph loop repeater, a telegraph subscribers station, a rstand a second relay in said loop repeater, an operating Winding, abiasing winding and an armature on each of said relays, said operatingand biasing windings on each relay each having one end connected to anindividual terminal for its respective relay. a. first and a secondconductor connecting saidhub repeater and said loop repeater, a thirdand a fourth conductor connecting said loop repeater and said station,said first conductor in a path extending from said hub repeater throughsaid operating winding on said rst relay to its individual terminal,said second conductor in a path extending` from said hub re peaterthrough said armature and a rst contact on said second relay to batteryof a first polarity, a circuit path extending from batteryrof said rstpolarityat said loop repeater through said third conductor, saidstation, said fourth conductor, said operating winding andterminal onsaid second relay and said armature and a rst contact on said iirstrelay to batteryrof a second polarity -for a rst signaling condition, afth conductor extending from said armature on 8 said second rrelay to asecond contact on said firstrelay, and a'path extending from saidbattery of said first polarity through said rst contact and aramatureonsaid second relay, said fth conductor and said second contact andarmature on said rst relay, when the armature of said first relay isactuated in response to a signal incoming oversaid rst conductor fromsaid hub `repeater to saidloop repeater.

p f WILTON T. REA.

REFERENCES y*CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

